Automatic circuit breaker



J. SACHS AUTOMATIC CIRCUIT BREAKER July 11, 1933. l Re. 18,894

original Filed April' 1o, 19:50 5`SheetS-Sheet 1 HVEUUF Y JDSg/D/y 535/75 J. SACHS July l1, 1933. AUTOMATIC CIRCUIT BREAKER Re. 18,894

original Fild April 1o, 193C 5 Sheets-Sheet 2.

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5 Sheets-Sheet 3 Original Filed April 10. 1950 J. SACHS AUTOMATIC CIRCUIT BREAKER original Filed April 1o. 1930 5 Sheets-Sheet 4 fnl/Enth!" y MUSEI/0]? 555/75 Af. 7/ o" QHZUFHQQ/ J. SACHS AUTOMATIC CIRGUIT'BREAKER 1930 5 Sheets-Sheet July -11, 1933.

Original Filed April l0,

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' t t Uri/lijf Ressuecl July v11, 1933 "UNITED STATES Re. 18,894 PATENT OFFICE JOSEPH SACHS, or WEST HARTFORD, CONNECTICUT AUTOMATIC CIRCUIT BREAKER v Original N'o. 1,840,978, dated January 12, 19-32, Serial No. 443,067, iled April 10, 1930. -Application for.E

. reissue filed April 27, 1933. Serial No. 668,234.'

This invention relates particularly to cir l cuit breakers ofthegeneral type disclosed in myiA patents for Auto-matic circuit breakers, N0.1, 812,812,N0. 1,811,970 and No. 1,812,843 all dated June 30, 1931.

One of the objects of the present invention is to provide in a circuit breaker of the type described an improved construction whereby adjustment, repair or replacement of parts may be very easily accomplished. To this end the contactmember and the parts immediately associated therewith are so construct ed and connected as to constitute a self-contained electro-responsive circuitcontrolling structure which is readily detachable from the supporting and operatin-g parts of the circuit breaker. v Arfurther object of the invention is to provide, for a circuit breaker of the type described, simple and inexpensive,` but nevertheless effective, means for minimizing arcinfr.

l further object of the invention is to provide a circuit breaker of the type described having a plurality of independently operable. circuit opening mechanisms connected and arranged for operation by a single operating means.

A still further object of the invention is to provide -a circuit breaker, particularly a circuit breaker of the type described, having a plurality of independently operable circuit opening mechanisms' so connected and interrelated with each other and with an operating means that the electro-responsive operation of one of the'm serves automatically to enable each remaining mechanism and alsojthe operating means to immediately move to their open-circuit positions'.

Other objects of the invention will be apparent from the following specification and claims. i y

In the accompanying drawings I have shown one embodiment of the invention, but it will be understood that the drawings are for illustrative purposes only and are not to be construed 4as defining or limiting the scope of the invention, the claims forming a part of this specification beingrelied upon for that purpose.

Of the drawings:

Fig. l is a perspective view of a circuit breaker appliance-embodying the invention, the said circuit breaker being adapted for Fig. 5 is a bottom View ofthe parts shown'A in Fig. .4, these parts being separated from thefbase which is shown in section along the line 5%-5 of Fig. 7.

Fig. 6 is an isometric View showing the several parts of one of the detachable electroresponsive circuit-controlling structures.

. Fig. 7 is a fragmentary side view showing var1ous lparts of 'the circult breaker 1n as-v .sembled relationship, the base being shown partly in section along the line 7 -7 of Fig. 5.

Fig. 8 is a fragmentary side View, partly diagrammatic, showing the movable parts in their normal closed-circuit positions.

Figs. 9, 10 land 11 are views, similar` to Fig. 8, but showing the mechanism of the circuity breaker in various other positions.

The appliance as shown has two circuit breaker mechanisms adapted to be included in different legs of a circuit and arranged for operation by a single operating means lor handle. As concerns some of the features of the invention it is immaterial whether a plurality of circuit breaker mechanisms be provided or only one; but as concerns other features of the invention the provision of two or more circuit breaker mechanisms under ever, that as concerns certain features of my invention the cabinet and the meterl service facilities are not essential and that the circuit breaker mechanism may be used entirely independently of these features.

As shown in Figs. 1 and 2 there 1s provided a main insulating base 1 on which all of the Iparts of the appliance are mounted. Carried by the base adjacent each circuit breaker mechanism is a block 2 which is preferably formed separately from the base,` although it may be integral therewith if desired. The

3 cooperates with thebase 1 and the-corresponding block 2 to substantially entirely close the corresponding circuit breaker mechanism. The two covers at the left and `right are preferably interchangeable, al#

though this is not essential. l

Carried bythe base 1 at each side thereof are two stationary electric contacts 4 and 5, these being spaced apart transversely and adapted to be en aged by movable contacts of the correspon ing circuit breaker mechanismto be presently described. Each of `the contacts 4 and 5 comprises a flat strip of metal bent as shown and having the contact .face thereof located in a transversev plane. The contacts are easily removable, being held in lace by means of nuts on screws 4and 5.

eferring particularly to Figs. 4 and 5, there is provided a standard 6 which carries all. of the movable parts of the appliance. This standard 6 comprises two side plates?, 7, which are held in spaced relationship to each other. The standard may be secured in place on the base 1 by means of screws 8 extending forward into cross members 9 formin parts of the standard 6.

Ilarried by the standard 6 is a movable supporting and operating element, and this element is preferably aY rotatable shaft 10 supported in bushings 1,1, 11 p`ro'ecting laterally from the side plates 7, 7. or moving the shaft 10 there is provided an operating means, which may include a handle 12 pivoted between the side plates 7, 7 and operatively connected with the shaft 10 in a manner to be presently described in detail. The shaft 10.serves as the means for supporting and moving one or more electro-responsive circuit-controlling mechanisms, two such mechanismsbeing shown inthe drawings at opposite ends of the shaft. 'In accordance with one phase of the invention, each of these cirinv Fig. 7.

gs-.Each circuit-controlling structure includes an element 13 in the form of a sleeve ada ted to t over the end of the shaft 10 as s own in Fig. 5. Rotatably mounted on the sleeve 13 is a contact member which .includes two spaced side plates preferably formed of insulating material. The plates of theright hand member are indicated at 14, 14, and those of the left hand member are indicated at 14, 14".4 The sleeve 13 is reduced in diameter and shouldered at its ends to receive the plates, and washers 13, 13-may be provided at each side. of each plate. After assembly the ends of the sleeve are turned o-r spun outward, as shown in Fig. 5, in order to hold the washers and plates in place.

Two laterally projectin movable contacts 16 and v17 are carriedv by t e contact member at the sides thereof, these contacts projecting laterally from the respective side plates 14, 14 and being adapted to be engaged with and disengaged from `the respective stationary contacts 4 and 5 which have already been described.l The said contacts 16 and 17 are in the form of metallic plates which project inward through slots 15,15 in the respective side plates 14, 14'. Extending transversely between the two side plates is an insulating bar 18, the ends of which also extend into the said slots 15, 15. The inner ends of the contacts engage the bar 18 at the rear face thereof and are held inplace by means of screws 19, 19. p

There is provided as a part ofthe movable self-contained structure an actuator 20 serving as the immediate means for moving or -actuating the contact member for normal switching purposes or to effect closing of the circuit after automatic opening thereof.

.The actuator 20 is pivotally movably mounted for movement about the same axis as the contact member, and in the'presentinstance the actuator 'is rigidlyv secured to the sleeve 13 so as to be movable about the axis ofthe shaft when the bushing and shaft are turned. As shown the actuator comprises an insulating element 21 mounted on the sleeve 13 between the plates 14, 14. The element 21 may have a drive lit on the sleeve, or it may be retained thereon by a small radial bushing 22 extending through registering holes'. The actuatoralso comprises two spaced arms 23, 23 secured to the element 21 and carrying at their outer ends a small roller 25 rotatable on integral trunnions 24.

As a part of the movable self-contained structure I also provide an electro-responsively controlled means including a normally operative mechanical connection between the actuator and the contact member which connection is operative t'o enable the actuator to operate the contact member to open and close the circuit for ordinary switching purposes and which is automatically released upon the attainment of abnormal current conditions soas to permit the contact member to automatically move independently of the screws 28, 28 which detach-ably hold `the strip the wellknown action of such bi-metallic strips. the drawings at' 26, this strip being substantially U-shaped and having the legs of the U connected respectively with the movable contacts 16 and 17. As illustrated there are connecting elements 27 27 engaged and held in place by the said screws 19, 19, and the end portions of the legs of the strip 26 are provided with holes through which extend in place on the connecting elements 27, 27.

It will be observed that the strip 26 provides an electrical connection between the two movable contacts 16 and 17, thus completing the circuit through the entire mechanism when the movable contacts 16 and 17 are in en agement with the stationary contacts 4 an 5.

.The strip 26 is so shaped and positioned that it serves in and of itself as a latch to hold the contact member and the actuator in normally fixed relationship with each other. For this purpose the strip 26 is provided with a pin 29.adapted to engage the roller 25.

Under normal conditions the strip 26 serves to mechanically connect the contact member and the actuator 20 so` that 4normal switching movements may be effected, but" structure is biased for movement in the circuit-opening direction, -in this case in the counter-clockwise direction, by means of a spring 30, surrounding the corresponding bushing 11. The spring is engaged at one end with the corresponding side plate 7 and at the other end with the inner one of the two spaced side plates 14, 14.

As already stated the self-contained structure that has been described,I isreadily detachable `from its supporting and operating element, that is, the shaft 10. To facilitate detachment the structure is held in place by indicated at the right in Fig. 5, thus facilitatclockwise or opening d1rect1on. A

a screw 31 extending through the'y bushing 422 and into a threaded hole 32 in the shaft.

It will be apparent that after disengaging the spring 30 and removing the screw 31 /the entire structure may-bev entirely removed as ing adjustments, repairs or replacement.

In'accordance with one phase of thel invention there are provided two or more circuit breaker mechanisms all arranged to be operated or controlled in a novel manner by means of a single operating member such as the handle 12. As conerns this phase of the invention it is not necessary that the circuit The bi-metallic strip is shown inV breaker mechanisms themselves be constructed in detail-as described or that they include self-contained detachable structures.

When there are two vor more mechanisms the several actuators 20, 20 are connected together for movement in unison, in this case lall of them being connected with the common operating shaft 10. For purposes of convenience the operating shaft 10 and the actuators carried thereby will be referred to collectively as the actuating member. In the present instance the operating means for the actuating member `is carried by the standard 6 and is located between the two circuit breaker mechanisms. This arrangement is desirable, but is not essential as concerns the broader aspects of the invention. The said operating meanshas already been referred to as preferably including the handlev 12. As shown in Figs. 4, 5 and 8, the handle 12 is pivotally mounted on a` pin 33 extending transversely between the side plates 7, 7 of the standard. As shown the handle comprisesa single piece of sheet metal which is extended at its inner endfas shown at 34. A link 35 is pivotally connected at 36 with the extension 34 of the handle and is pivotally connected at 37 with an arm 38 projecting radially from the shaft 10. A `suitable means is provided for limiting the movement of fthe handle and there is-shown for this purpose a transverse pin 39 extending through an arcuate slot 40 in the handleextension 34. It will'be evident that movement of the handle 12 may be transmitted through the link 35 and the arm 38 to turn the actuating member and thus operate the contact members.

As already pointed out the contact members are biased for movement-in the opening direction, that is, in the counter-clockwise or opening direc/ti'on'by means of the springs 30, 30. The said contact members are additionally; urged in the opening direction by means of the resiliency of the stationary contacts 4 and 5. When the actuating member ismin its closed-circuit position as shown in Fig. 8 the two toggle links 34 and 35 occupy the positions shown with` the pivotal axis at 36 in front of va straight line connecting the pivotal axes at 33 and37. Movement of the links toward the front is prevented by l the stop pin 39 and thus the two links 34 and 35 constitute a restraining means positively resisting the tendency o f the contact members to automatically move in the counter- Provision is made whereby each electroresponsive means serves upon the passage ofA excess current not only to release lts own contact member for movement independently of move to their open-circuit positions. The action of the electro-responsive means upon the restraining means will depend upon the type of restraining means selected, but when the restraining` means comprises toggle links as -shown I preferably provide means which bias the said links for movement out of their locking position. As shown this means is a spring 41 which tends to move the handle 12 in the counter-clockwise direction and therefore tends to-move the links 34 and 35 in the direction to break the toggle. I have 'already pointed out vthat the links are held Fig. 8 shows the circuit breaker with all v ofthe parts in closed-circuit positions, Vthe toggle links 34 and 35 serving as restraining means ,to prevent the movement of any of the parts to their open-circuit positions. By means' of the handle 12 theactuating member and `all of the contact members can be moved,`

while remaining in fixed relationship. to each other, to their open-circuit positions as f shown in Fig. 11. It will be understood that y during such movement. the thermalstrips 26,

26 remain in engagement with the respective actuators 20, 20, and that thus the handle l 12 can be used to operate' the circuit breaker as a switch to open and close the circuit for ordinary switching purposes. Duringsuch I operation the Contact members are positive- 40 ly moved in the clockwise circuit-closin direction by reason of the engagement o the thermal strips 26, 26 with theactuators 20, 20

Y and the said contact members are moved in the counter-clockwise. circuit-opening direction bythe spring 30, 30 acting under the control of the actuators and the handle.

The

counter-clockwise movement of each contact member is limited by a stop 42 carried/by the corresponding block 2. The stop comprises a metal strap 42a held in place by the screws 2a,- 2, 4and also comprises small blocks 42",

i 42b ofinsulating material having holes thereplace by means of a Cotter pin 42.

in through'wliich the strap 42 extends to support -the blocks-, The blocks are retained in As already pointed out each thermal strip 26 is so constructed and adjusted that upon the attainmentvof abnormal current condi-- tions, as for instance upon passage of a current 1n excess of a predetermined amount,

. .it will be deflected upward and rearward.

.When the current in the strip exceeds the,

' said predetermined amount the strip will disengage the actuator 2O` thus breaking the mechanical connection between' the actuator -and the contact member. lAssoon as this mechanical connection is broken the contact member is immediately turned in the counter-clockwise direction under the action of the corresponding spring 30y to the open-circuit position, the circuit being thus broken in two places as already described.

It will be understood that theautomatic movement ,of either contact member to its open-circuit position takes place entirely independently of the actuating member and will so take place even though the actuating -anyone to prevent the operation of any one of the circuit breaker mechanisms by holding or fastening the handle in its closed-circuit position. f

As already stated, the spring 41 is of such strength as to be insuiicient to break the toggle at 34, 35 when all of the contact members are biased in the opening direction by reason of'the action of the springs 30, 30 and of the resilient contacts 4, 4 and 5, 5. However when either of the thermal strips 26, 26 vacts to disengage the actuating member and release the corresponding contact member, the pressure upon the toggle links is reduced. The strength of the spring 41 is such that, upon the reduction of pressure resulting from the electro-responsive release of any one contact member, itk immediately acts to move the actuating member and each remaining contact member to their open-circuit positions. y

Fig. 10Vshows the right hand contact mem- .ber as having been released and as having started its automatic movement in theopening direction. The release of this right hand contact'member has reduced the pressure on the toggle links 34, 35 suiiciently to vpermit the spring 41 to act, and the spring has already started the movement of the en tire operating mechanism and of the remaining left hand contact member toward their opencircuit' positions. This movement continues "with the right hand Acontact member slightly in advance of the left handy contact 'member until the full open positions are reached as shown in Fig. 11, wherein the contact members' are in their full open-circuit positions as limited by thestops 42. The mechanical connection between the. released right hand I contactmember and the corresponding;r actuator 20 is automatically restored as the opencircuit position is reached,by reason of thereengagement ofthe thermal strip 26 with the roller 25 of the actuator. Thus the complete normalrelationship of the parts is re-established and the circuit can be reclosed if de- No.,1,812,842 I have disclosed two insulating walls at opposite sides ofthe path of movement of each movable contact, these walls..

serving to confine any gases that may be formed as the result of arcing kand to thus minimize arcing manifestations. In accordance with the present invention I 'provide atljacent. each pair of contacts not only the two opposite walls (the outer surface of the plate 14 or 14a as shown in Figs. 4 and 5 and the adalso a third wall (the surface of the block 2 in which are formed the slots 43, 43 as shown in Fig. 7) which third wall extends transverse`-` ly between the first said walls. As shown thev wall at the third side is arcuate so as to con-v form approximately to the'arcuate pa'lftliof,

ese"

movement of the movable contact. three walls constitute insulating` means assof ciated with the contacts and closely adjacent` three sides` of the path of circuit-opening movement of each movable contact. The? said -three walls serve to much more effectivewA ly conne the arc-formed gases than can be done with only said Patent No. 12,842".

It will be observed that each plate 14. or 14a constitutes a shield between the bi-metallic thermal latch 26 and the rupturing position of the. corresponding contacts, thus effectively protecting the said latch from any arcing manifesta-tions.

In order to still further minimize arcing I preferably provide means embodying the principles set forth in my Patent No. 1,554,- 528 dated September 22, 1925. The insulating block 2 is provided at both sides with slots or vents 43, v43, in order tol form two series of chambers in close proximity to Athe respective paths of movement -of the 'movable contacts, these vchambers being adapted for receiving and condensing arc-formed gases. The inner endsof the slots 43, 43 are shown as being at the beforcmcntioned curved surfaces or walls which conform to the arcuate paths ofthe movable contacts, but as to this detail I do not limit myself. I't will be obvious that when the circuit is broken by the movement of the contacts 16 and 17 from the closed position to the position vshown by full lines in Fig. 7, the gases resulting from any arcs that may be formed will pass` upward into the slots 43, 43, being thus'cooled and distivo walls,'as disclosed iny my sipated so as to prevent the continuation of the arcing action. It will be observed that the slots 43 constitute vents for the arcformed gases, these vents communicating with the arcing zones of the respective pairs of contacts and extending to the exterior of the insulating means consisting of the insulating; members 1, 2 and 3. The vents are shown as being straight, but as to this I do not limit myself. Preferably and as shown. the vents for each paif of contacts terminate at an end portion of the said insulating means, and preferably all of the vents terminate at the same end portion.

1 vvFor the attachment of circuit wires, terminals 44e, 44 and 45, 45 may be secured'to the base 1 by means of nuts on screws 46, 46 and y47, 47 and they are connected electrically with the respective stationary contacts 4, 4 and 5, 5. The terminals 44, 44 may be regarded as I -adapted for a connection of service wires S, S jacent parallel opposltely facing surfaces of the insulating base 1 and the cover 3), but y;

and the terminals 45, 45 may be regarded as wires forming the third or neutral connec- The two screws 46 and 47 are so spaced as to be adapted to receive a by-pass link A shown `nal independently of the circuit breaker mechanism. As already described parts of the circuit breaker mechanism are removable, and with the current by-passed as described the said parts of the circuit breaker mechanism can be removedfor adjustment, repair or replacement without interrupting the electrical connection between the service and load wires.

If the circuit breaker is to be used independently of an electric meter, the terminals 44 and 45 of each pair may be connected directly with the corresponding stationary con tacts 4 and 5. However, when the 'app iance is intended for use in conjunction with an electric meter such as M and when the complete device is required Vto include meter testing facilities I prefer to provide the elec-` trical connections which will ',now vbe described, referencevbeing hady particularly to Fis. 1 and 3.

ach stationary contact 4 is connected by means of the offset conductor member 50 with the corresponding wire terminal 44 and the companion stationary contact 5 is connected through al conductor 50L with a threaded rod 51 which is positioned to extend directly forward through a hole inthe front of the adapted for the connection of load wires L, L. #For a three wire circuit there maybe addi- .,tional terminals 48 and 49 adapted for the connection of additional service and load 52 similar to the rod 51 and similarly extending through a hole in the front of the cover. Wlre terminals 53 and 54 are mounted on the front ofthe block 2, being adapted to be connected respectively with the service and load sides of the meter. The terminals 53 and 54'are electrically connected respectively with vertical straps 55" and 56, having threaded holes near the lower ends thereof.

On the front of each removable cover 3 A'I provide conductors which serve when the f cover is in place to provide electrical connection between the rods 51 and 52 and the straps 55 and 56. The rods 51 and 52 extend through and are electrically connected vwith vertical straps 57 and 58 mounted on the cover, the rods preferably having integral collars thereon which directly engage the rear surfaces of the straps. The straps 57 and 58 are held in place by screws 59 and 60. Nuts on the rods 51 and 52 engage the straps 57 and 58 to provide firm electrical connections and also serve to assistL in 'holding the cover in place. Also mounted on the cover in alignment with the vertical straps 57 and 58gare other vertical straps 61 and 62 held in place by screws 63 and 64. The upper ends of the straps 61 and 62 normally overlap the straps 55 and 56 and are detachably connected thereto by means of screws 65 and 66 entering the threaded holes therein. The straps 57 and 58 are spaced from the straps 61 and 62 but they are normally electrically connected therewith by means of removable test links 67 and 68 normally heldin place by means of nuts engaging the screws 59, 60 and 63, 64. From an inspection of Figs. 1 and 3 ,it will be evident that when the circuit breaker mechanism is in closed position a circuit is established from the service wire terminal 44 through the conductor 5() and through the stationa and movable contacts of the circuit brea er proper to the rod 51. From the rod51 the circuit extends through the parts 57, 67, 61, 55 andv53 to the meter. From -the meter the circuit extends through the parts 54, 56, 62, 68 and 58 to the rod 52, this rod being electrically connected with the load wire terminal 45.

The conductors and links at the front of the cover 3 will be recognized as constituting testing facilities of a well known type. By putting in place a by-pass link between the screws 51 and 52 as indicated by dot-anddash lines at B in Fig. J1, the current canl bc by-passedcfrom the service wire to the load wire without going through the meter. It will be observed however that the by-pass- .ing between the screws 51 and 52 leaves the circuit breaker in the circuit, thus providing protection for the customer during testing;r

vand making it possible to manually control n l I l the customers circuit during testing 1f desired. One or the other or both of the meter terminals may be freed for testing by removing oneor the other or both of the links 67 I and 68 inaccordance with well known pracl Without this arrangement Y the test links and their associated conductors would have to be located either at the side of the circuit breaker proper or at the top or at the bottom thereof, thus making necessary a very much larger enclosing box.

For enclosing the entire appliance I have shown a cabinet 69 of sheet metal having a rear wall 70, side walls 71 and 72 and end walls 73 and 74. The upper end w'all 74 preferably has an opening therein which adapts the cabinet for direct relationship with the electric meter M. The cabinet has an openable front cover 75 which is shown as being hinged at 76, 76 to the bottom end wall 73 and which is normally held closed by a latch at 7 7. The cover has a slot 7 8 therein vthrough which the operating handle 12 extends. v

I do not herein claim the features of invention involving the relationship between the circuit breaker mechanism proper and the bypassing and meter testing facilities, as these features are disclosed and claimed in my patent for Electric meter service appliance No. 1,840,979 dated January 12, 1932.

What I claim is: l v

1. A self-contained detachable electro-responsive circuit controlling structure for an automatic circuit breaker com rising in combination, an element detachagly connectible with a movable supporting and operating means, an actuator rigidly connected With the said element, a contact member relatively' movably carried by the said element and normally connected with the actuator so as to be moved thereby to open and close the circuit, a contact on ythe contact member adapted to engage and disengage a stationary contact, and an electro-responsive device normally movable with the said actuator and contact member and electrically connected in the cir- Y cuit to be controlled and with the contact on the contact member so as to automatically serve upon the passage of excess current to release the contact member from the actuator and thus permit the said member to automatically move in the circuit-opening direction independently of the actuator.

2. lA circuit controlling structure as set forth in claim 1, wherein the. electro-responsive device is an electro-thermally responsive metallic strip serving in and of itself as an 5 automatically releasable latch to normally connect the conta-ct member with the actuator.

3. An"l automatic circuit breaker comprising in combination, two stationary contacts, amovable operatingand supporting means, an element detachably connected with the said supporting and operating means, an actuator rigidly connected with thc said elelment, a contact' member relatively movably carried' by the said element and normally releasably connected with the actuator so as to be moved thereby, two contacts on the contact member adapted to engage and disengage the stationary contacts to open and close the circuit, and an electro-responsive device normally movable with the said actuator and contact member and electrically connected between the contact on the contact member so as to automatically serve upon the passage of excess current to release the contact member from the actuator and thus permit the saidmember to automatically move in the circuit-opening direction independently of the actuator.

4. An automatic circuit breaker comprising in combination, a pivotally movable actuator, av Contact member pivoted coaxially withthe actuator and biased for opening movement independently thereof, a stationary electric contact, a movable electric contact on the Contact member engageable with the stationary contact, an lelectro-responsively controlled mechanical connection between the actuator and the contact member normally enabling the former to move the latter to engage and disengage the said contacts, the said mechanical connection being automatically releasable upon the attainment of abnormal current conditions to permit automatic opening movement of the contact'member, and stationary means providing a series of slots having their ends located closely adjacent the path of movement of the movable' contact sovas to serve to break up any arcs that may be formed.-

5. A11 automatic circuit breaker comprising in combination, a pivotally movable actuator, a contact member pivoted coaxially with the actuator and biased for opening tionary electric contacts at the respective sides of the contact member, two movable electric contacts on the contact member at the sides thereof engageable respectively with the stationary contacts, an electro-responsively controlled mechanical connectio-n bey tween the actuator and the contact member normally enabling the former to move the latter to engage and disengage the said contacts, the said mechanical connection being automatically releasable upon the attainment movement independently thereof, two staof abnormal current conditions to permit automatic opening vmovement of, the contact member, and stationary means providing two series 'of Y slots having their ends located closely adjacent the respective paths of move4 70 ment of the movable contacts so as to serve to l break up any arcs that may be formed.

6. In a. multiple poled automatic circuit breaker, the combination of a movable actuating member, a plurality of independently movable circuit breaker Contact members, each having a contact for breaking one leg of the circuit independently of any other leg and each independently biased toward its open-circuit position, and a plurality of electro-responsive means each comprising an element inherently responsive to abnormal' current conditions in-one leg of the circuit and constituting at least a part of a mechanical connection between the corresponding actuating and contact members normally operative to prevent independent circuit opening movement of the latter, each said element upon the attainment of an abnormalcurrent condition in the corresponding leg of the circuit being relatively movable by reason of its own inherent electro-responsive characteristics so as to render the corresponding mechanical connection ineffective and to thereby permit the corresponding contact member to move to its open-circuit position independently of the actuating member and independently of each other contact member..

7. A multiple poled automatic circuit breaker as set forth in claim 6, wherein each 10 electro-responsively movable element is a latch carried by one of the corresponding contact and actuating members and normally having a direct engagement with the other, the said latch being automatically disengaged from lthe said other member upon the attainment of an 4abnormal circuit condition so as to permit independent movement of the contact member. l

8. In a multiple poled automatic circuit 11 breaker, the combination of a movable actuating member, a plurality of independently movable circuit-breaker contact members,

each having a contact for breaking one leg of the circuit independently of any other leg l and each independently biased toward its open-circuit. position, and a plurality of electro-responsive means bodily` movable with the' actuating member and contact members and respectively including mechanical connections normally operative to enable the actuating member to move all of the contact members in unison to open or close the circuit, each mechanical connection being automatically releasable upon the attainment of ob- 12? normal current conditions in the corresponding leg to permit automatic opening movement of the corresponding contact member independentlyof the actuating member and independently( of any other contact member. 13

l responsive means bodily movable with the ac- 1 tuatlng member and contact members and respectively including mechanical connections normally operative to enable the actuating member to move all of the-contact members in unison to open or close .the circuit, each mechanical connection being automatically releasable upon the attainment of abnormal current conditions in the corresponding leg to `permit automatic opening movement of the corresponding Contact member independently of the actuating member and independently of any other contact member, a movable operating means, and means connected between the operating means and the actuatingV member lenabling the former to operate the latter, the saidl means also serving to releasably hold the actuating member in its closedcircuit position.

1 0. In a multiple poled automatic circuit breaker, the combination of a shaft rotatably supported between its ends, two actuators secured to the respective projecting end portions of the shaft, two independently movable circuit breaker contact members on the said end portions of the shaft adjacent the respective actuators, each having a contact for breaking one leg of the circuitindependently of any other leg and each independently biased toward its open-circuit position, and a plurality of electro-responsive means bodily movable with the actuators 'and contact mem' bers and respectively including mechanical connections normally operative to enable the shaft and actuators to move all of the contact members'in unison to open or close the circuit, each mechanical connection being .automatically releasable upon the attainment of abnormal current conditions in the corresponding leg to permit automatic opening movement of thecorresponding contact member independently of the actuating member and independently of any other contact member.

11. In an automatic circuit breaker, the combination of a movable operating means biased for movement in the circuit opening direction, a plurality of independently movable circuit breaker contact members, a plurality of electro-responsively controlled means respectively including mechanical connections normally operative to enable the operating means to move all of the contact members in unison to open or close the circuit, each mechanical connection being automatically releasable upon the attainment of abnormal current conditions to permit automatic open ing movement of the corresponding contact member independently of the operating means and independently of any other contact member, and a restraining means separate from the said contact members and mechanical connections for releasably holding the operating means in its closed-circuit position so long as all of the contact members are in their closed positions, the said restraining means `upon the electro-responsive release of any one contact member being automati' cally released to permit immediate movement in the opening direction of the operating means and of each remaining contact'member.

12. In an automatic circuit breaker, the combination of a movable actuating -member biased toward its open-circuit position, a plurallty of independently movable circuit breaker contact members each normally connected with the actuating member for movement therewith to open and close the circuit, a plurality ofelectro-responsive devices associated with the respective contact membersl and each serving upon the attainment of abnormal current conditions to release its contact member so as to permit automatic opening movement thereof -independently of the actuating member and independently of any other contact member, and a means for releasably holding the actuating member in its closed-circuit position so long as all of the contact members are in their closed positions, the said means upon the electro-responsive release of any one contact member being automatically released to permit immediate movement in the opening direction of the actuating member and of each remaining contact member. Y

13. In an automatic breaker, the combination of a movable operating means biased for movement in the circuit opening direction, a movable actuating member connected .with the operating means to be operatedy thereby, a plurality of independently movable circuit breaker contact members each normally connected with the actuating member for movement therewith to open and close the circuit, a plurality of electro-responsive deviceslassociated with the respective contact members and each serving upon the attainment of abnormal vcurrent conditions to release its contact member so as to permit automatic opening movement thereof independently of the -actuating member and independently of any other Contact member, and a means for releasably holding the operating means and actuating memberin their closed-circuit positions so long asy all of the Contact members are in their closed positions, the said means upon the electro-responsive release of any .one contact member being automatically released 'to permit immediate movement in the opening' direction of the operating means and actuating member and of each remaining contact member.

14. An automatic circuit breaker as set forth in claim 13, wherein the actuating member and all of the contact members are pivotally movable about a common axis.

15. An automatic circuit breaker vas set forth in claim 13,.Wherein eachelectro-responsive means isnormally bodily movable with its corresponding contact member.

16. In an automatic circuit breaker, the combination of a movable operating means biased for movement in the circuit opening direction, a plurality of movable circuit breaker contact members each biased for open- 1 for holding the operating means in its closedcircuit position so long as the tendency thereof to move to its open-circuit position is rsisted by all of the contact members as the result of the normal bias thereof, the said means, upon the reduction of the said pressure as the result of the electro-responsive release of any one contact member, being rendered ineffective so as to permit immediate movement in the opening direction of the operating means and of each remaining contact member. s

17. An automatic circuit breaker as set forth in' claim 16, wherein there is a spring tending to render the releasable hol-ding means inoperative, and wherein the pressure n' action oi the spring.

exerted by all of the contact members is sufficient to prevent action of the springand the pressure exerted by one less than all. of the contact members is insuliicient to prevent 18. An automatic circuit breaker as set .y torthcin claim 16, wherein the releasable holding m-eans'is separate from the said contact members and mechanical connections.

19. An automatic c1rcu1t breaker as set i forth in claim 16, whereinheach mechanical connection after automatic release thereof is4 automatically restored to its operative condition as the result of the automaticmovement of the operating means to its open-cir- 'cuit position.-

20. In' an automatic circuit breaker, the combination of a movable actuatmg'member biased toward its open-circuit position, a

Aplurality of independently movable circuit breaker contact members each normally cony nected with the actuating-member for movement in fixed relation therewith to open and close the circuit, a plurality of electro-rf sponsive means associated with the respective contact members and each serving upon the attainment vof abnormal current conditions to release its contact member so as topermit automatic opening'A movement thereof independently of the actuating member and in dependently of any other contact member, and releasable means normally operative for holding the actuating member in its closedcircuit position so long as pressure is exerted on the actuating member by all of the contact members as the result 'of the normal bias thereof, the said holdingmeans, upon the reduction of the said pressure as the result of the electro-responsive release of any one contact member, being rendered ineffective so as to permit immediate movement in unison in the opening direction of the actuating member and of each remaining contact member.

21. An automatic circuitbreaker as set forth in claim 20, wherein each electro-responsive means is a bodily movable electrothermally responsive metallic strip serving in and of itself as an automatically releasable latch to normally connect the corresponding contact member with the actuating member.

22. In an automatic `circuit breaker, thecombination of a movable actuating member biased toward its open-circuit position, a plurality of independently movable circuit breaker Contact members, a plurality of electro-responsive means respectively including mechanical connections normally operative to 4enable the actuating member to move all of the contact members in unison to open or close the circuit, each mechanical connection being automatically releasable upon the attainment of abnormal current conditions to permit automatic opening movement of lthe corresponding contact member independently of the actuating member and independently ofany other contact member, and means including toggle links for operating the actuating member, the. said toggle links being in their `locking relationship when the actuating member is in its closedcircuit position and being automatically moved out ofthe said locking relationship upon the electro-responsive release of any `one contact member to thereby permit immediate movement in the opening direction of the'operating means and of each remaining' contact member.

23. Inan automatic circuit breaker, the combination of a movable actuating member, a plurality of independently movable circuit breaker contact members each normally connected with the. actuating member to be moved thereby to open and close the circuit, a plurality of electro-responsive devices associated with the respective contact members and leach serving upon the attainment of abnormal current conditions to reooA lease its contact member so as to permit automatic opening movement thereof independently of the actuating member and independently of any other contact member, means including toggle links for operating the actuating member, the said toggle links i being in their locking relationship when the actuating member is in its closed-circuit position and being held in the said relationship by the pressure resulting from the bias of the contact members, and a spring tending to move the toggle links out of their said' circuit breaker, of a stationary contact, a

movable contact adapted to engage and disengage the stationary contact, the last said contact being biased for Imovement in the circuit-opening direction and being normally held mechanically against such movement, an electro-responsive element bodily movable with the movable contact and arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to mechanically release the said contact and thus permit it to automatically move to open-circuit position, and insulating means associated with the contacts and comprising Walls closely adjacent three sides of the path of movement of the movable contact.

25. vThe combination in an automatic circuit breaker, of two stationary contacts, two movable `electrically connected contacts adapted to engage and disengage the respective stationary contacts, the last said contacts being biased for movement in the circuit-opening direction and being normally held mechanicallyT against such movement, an electro-responsive element bodily movable with the movable contacts and arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to mechanically release the said contacts and thus permit them to automatically move toppen-circuit positions, and insulating means associated with the contacts and comprising Walls closely adjacent three sides of the path of movement of each movable contact.

'26. The combination in an automatic circuit breaker, of tWo stationary contacts, a movable actuator, two movable contacts adapted to engage and disengage the respective stationary contacts and biased for movement in the circuit-opening direction, a thermally responsive bi-metallic strip bodily movable with the movable contacts and electrically connected between them, the said strip normally serving as a latch to mechanically connect the movable contacts with fhe actuator and the said strip upon being heated by an abnormal current therein serving to mechanically release the said contacts and thus permit them to automatically move to open-circuit position, and insulating means associated with the contacts and comprising walls closely adjacent three sides of the path of movement of eachvmovable contact.

27. The combination in an automatic circuit breaker, of a stationary contact, a movable contact adapted to engage and disengage the stationary contact, the last said contact being biased for movement in the circuit-opening direction and being normally held mechanically against such movement, an electro-responsive element bodily movable with the movable contact and arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to mechanically release the said Contact and thus permit it to automatically move to opencircuit position, and three insulating walls closely adjacent three sides of the path of movement of the said movable contact, at least one of the said walls being stationary and at least one of the said walls being movable with the movable contact.

28. The combination in an automatic circuit breaker, of a stationary contact, a movable contact adapted to engage anddisengage the stationary contact, the last said contact being biased for movement in the circuitopening direction and being normally held mechanically against such movement, an electro-responsive element bodily movable with the movable contact and arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to mechanically release the said contact and thus permit it to automatically move to open-circuit position, stationary insulating means comprising two walls closely adjacent two sides of the path of movement ofthe movable contact, and an insulating means movable with the movable contacts and comprising a wall adjacent a third side of the path of movement of the movable contact, the said movable insulating means also serving to shield the electro-responsive element from the rupturing position of the contacts. I

29. The combination in an automatic circuit breaker, of a stationary contact, a movable actuator, a movable contact adapted to engage and disengage the stationary contact and biased for movement in the circuit-opening direction, the said movable contact being normally mechanically connected with the actuator to be moved thereby, an electro-responsive element bodily movable with the movable contact and with the actuator and arranged to be energized upon the attainment of an abnormal current condition-in the circuit so as to mechanically release the movable contactfrom the actuator, stationary in- Sulating means comprising two Walls closely 30. The combination in an automatic circuit breaker, of a stationary contact, amovable actuator, a-movable contact adapted to' I engage and disengage the stationary contact and biased for movement in thecircuit-opening direction, a thermally responsive bimetallic strip bodily movable with the movable contact and electrically connected in the circuit, the said strip normally serving as a latch to mechanically connect the movable contact with the actuator and the said strip upon being heated by an abnormal current therein serving to mechanically -release the said contact and thus permit it to automatically move to open-circuit position, stationary insulatlng meansv comprising two walls closely adjacent two sides of the path of movement of the movable contact, and an insulating means movable with the movable,

contacts and comprising a wall 'adjacent a third side of the path of movement of the movable contact, the said movable insulating means also serving to shield the said bi-metallic strip from the rupturing position of the contacts.

3 1. The combination in an automatic circuit breaker, of two stationary contacts, a movable actuator, two movable contacts adapted to engage and disengage the respective stationary contacts and biased for movement in the circuit-opening direction, a thermally responsive bi-metallic strip bodily movable with the movable contacts and electricallyn connected between them, the said strip normally serving'as a latch to mechani` cally connect the movable contacts with the actuator and the said strip upon being heated by an abnormal current therein serving to mechanically release the said contacts and thus permit them to automatically move to open-circuit position, stationary insulating means comprising two walls closely adjacent two sides of the path of movement of each movable contact, and an insulating means movable with the movable contacts and comprising walls adjacent a third side of the path of movement of each movable contact, the said movable insulating means also serving to shield the said bi-metallic strip from mechanically againstsuch movement, an electro-responsive element bodily movable with the movable contactA and arranged 4to be energized upon the attainment of an abnormal current condition in the circuit so as to mechanically release the said contact Aand thus permit it to automatically move to open-circuit position, and insulating means associated with the contacts and comprising walls closely adjacent three sides of lthe path of movement of the movable contact, the said insulating means having therein a slot adjacent the path of movement ofthe movable contact.

33. The combination in an automatic circuitbreaker, of astationary contact, a movable contact adapted to engage and disengage the stationary contact, the last said contact being biased for movement in the circuitopening direction and being normally held mechanically against such movement, an electro-responsive element arranged to be energized upon the attainment of an-abnormal current condition in the circuit so as to mechanically release the said contact and thus permit it to automatically move to opencircuit position, and stationary insulating means substantially completely enclosing the contacts and comprising walls closely adjacent the path of movement of the movable contact, the said insulating means having therein a vent communicating with the arcy ingzone of the contacts and extending to the exterior of the saidinsulating means.

34. The combination in an automatic circuit breaker, of two stationary contacts, two movable electrically connected contacts adapted to engage and disengage the stationary contacts, the last said contacts being biased for movement in the circuit-opening direction and being normally held mechanically against such movement, an electroresponsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to mechanically release the said movable contacts and thus permit them to automatically move to opencircuit positions, and stationary insulating means substantially completely enclosing the contacts and including walls closely adjacent the path of movement of each -movable contact, the said in'sulatingmeans having therein two separate vents each communicating vwith the arcing zone of the corresponding pair of contacts and extending to the exterior of the said insulating means.

S35/The combination in an automatic circuit breaker, of two stationary contacts, two movable contacts adapted to engage and disengage the stationary contacts, the last said contacts being biasedfor movement in the circuit-opening direction and being normally held mechanicallyagainst such movement, an electro-responsive element bodily movable with the movable contacts' and electrically connected between them to be energized upon the attamment of an abnormal current con- I.dition in the circuit so as to mechanically pair of contacts and extending to the exterior of the said insulating means.

36. The combination 1n an automatic circuit breaker, of two stationary contacts, two

movable electrically connected contacts adapted to engage and disengage the stationary contacts, the last said contacts being biased for movement in the circuit-opening direction and being normally held mechanically against such movement, anelectro-responsive element arranged to'be energized upon the attainment of an abnormal current4 condition in the circuit so as to mechanlcally release the said movable contacts and thus permit them to automatically move to opencircuit positions, and stationary insulating means substantially completely enclosing the contacts and comprising walls closely adjacent the path of movement of each movable contact, the said insulating means having therein two separate vents each communicating With the arcing zone of the corresponding pair of contacts and each extending to and terminating at an end portion of the said insulating means.

37. The combination in an automatic circuit breaker, of two stationary contacts, two movable electrically` connected contacts adapted to engage and disengage the stationary contacts, the last said contacts being biased for movement in the circuit-opening direction and being normally held mechanically against such movement, an electro-responsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to mechanically release the said Vmovable contacts and thus permit them to automatically move to open-circuit positions, and stationary insulating means substantially completely enclosing the contacts and comprising walls closely adjacent the path of'movement of each movable Contact, the said insulating means having therein two separate vents each communicating with the arcing'zone of the corresponding pair of contacts and ei:-v tending to and terminating at the same end portion of the said insulating means.

38. In an automatic circuit breaker, the

- combination of a movable actuating member,v

a plurality of independently movable contact members each provided with a movable Contact, a plurality of stationary contacts as y associated parts to positively force. the movable contacts into firm engagement with the stationary contacts and to lock them in such engagement.

39. In an automatic circuit breaker, the combination of a movable actuating member, a' plurality of independently movable Contact members each provided with a movable contact, a plurality of, stationary concontacts, a plurality of bodily movable current-carrying bi-metallic latches normally enabling the actuating member to move all ot' the contact members in unison, each latch being automatically releasable upon the attainment of abnormal current conditions to permit automatic and independent contactdisengaging movement of the corresponding .contact member, and operating means for the actua-ting member including toggle links which serve in cooperation with the releasable latches and other associated parts to positlvely force the movable 4contacts into iirm engagement with the stationary contacts and to lock them in such engagement.

40. In an automatic circuit breaker, the combination of a movable actuating member,

a plurality of independently movable contact members 'each provided with a pair of movable contacts, a plurality of pairs of stationary contacts associated with the respective pairs of movable contacts, a plurality of bodily movable current-carrying bi-metallic latches normally enabling the actuating member to move all of the ,contact `members in unison, each bi-metallic latch being electrically connected between the movable contacts of the corresponding pair and being auto` matically releasable upon the attainment of abnormal current conditions to permit automatic and independent contact-disengaging movement of the corresponding contact member, and operating means 'for the actuating -member including toggle links which serve in cooperation with the releasable latches and other associated parts to positively force the movable contacts into firm engagement with the stationary contacts and to lock them in such engagement.

In testimony whereof I have hereunto set my hand this 25th day of April, 1933.

JOSEPH SACHS.

-t-acts associated with the respective movable 

